The Nigerian armed forces have fought back against the Islamic militant group Boko Haram, killing 13 suspected combatants in an attack on their stronghold in the town of Maiduguri on Tuesday.

The news was confirmed by the Joint Task Force Operation Restore Order, who said that they lost one soldier in the gunfight, CNN reported. Military spokesman Sagir Musa said that that Boko Haram have been carrying out "incessant callous, brutal, barbaric and impious killings," and Human Rights Watch estimate that the Islamic group, whose name means "Western education is sacrilege," have killed more than 2,800 people in the last several years, including at least 34 since Christmas.

On Christmas Eve, raids on two separate churches resulted in the deaths of 12 worshippers, including a pastor. Another 15 Christians were massacred six days later on Sunday at another church in Northern Nigeria.

"We had warned that Boko Haram would continue its tradition of killing Nigerian Christians on Christmas day. Last week marked the third straight year that the terror group has murdered Nigerian Christians in the church on a Christmas day," a statement by the Christian Association of Nigerian-Americans noted, calling for more action on behalf of authorities.

Nigerian President Goodluck Jonathan has said that despite these setbacks, Nigeria has been battling the terrorists, and a number of those who carried out the attacks have been apprehended "as a result of the diligence and steadfastness of law enforcement agents and security operatives across the country." Jonathan made the remarks at a New Year's service at Saint Anglican Church in Abuja, but did not reveal how many in total were in custody, AllAfrica reported.

Boko Haram have been bombing and burning churches and attacking Christians across the Muslim-dominated northern Nigeria for years, specifically targeting Christians in their mission to eradicate them from the country.

"The Nigerian state and Christians are our enemies and we will be launching attacks on the Nigerian state and its security apparatus as well as churches until we achieve our goal of establishing an Islamic state in place of the secular state," the militants stated in no uncertain terms back in June.

Despite the slaughter of Christians and innocent people in Nigeria, the U.S. government has been reluctant to designate Boko Haram a terrorist organization, even though it has said some of its leaders are terrorists.

"Our government in Washington DC, especially the White House and the State Department are fully aware of what is going on. But both President Barack Obama and outgoing Secretary of State Hillary Clinton have simply tolerated this impunity by their inaction," the Christian Association of Nigerian-Americans said about the petition.

"Already, American citizens have been affected, and the United Nations building in Abuja has been attacked by these terrorists. The U.S. Congress has affirmed that Boko Haram is a threat to the U.S., especially with the group's suspected links to al-Qaeda."